This invention relates to a television picture size altering apparatus and, more particularly, a picture compressor for reducing a picture from its original full raster size to a fraction of that original size.
A television picture size altering apparatus for changing the size of the television picture is described in application Ser. No. 754,688 of Robert N. Hurst, filed Dec. 27, 1976 entitled "Television Picture Size Altering Apparatus," now U.S. Pat. No. 4,134,128. In the example given in the above cited application, the apparatus reduced a full raster to one-quarter of the original size. In that application, it was pointed out that a reduced size picture could be obtained by deleting some of the picture elements or samples of the original signal while maintaining other picture elements of the original signal. The picture samples that were maintained were placed next to one another filling in the holes, resulting from the deletion of the other picture samples. This technique does produce a reduced size picture as is described, however, the display picture may exhibit unacceptable television moire patterns. These moire patterns result from sampling the signal below the Nyquist rate.